Salt tolerance and foliar spectral responses in seedlings of four ornamental herbaceous species

Authors: DE OLIVEIRA, ADRIANA - Universidade Federal Do Ceara (UFC); DE LACERDA, CLAUDIVAN - Universidade Federal Do Ceara (UFC); CAVALCANTE, SANTOS - Universidade Federal Do Ceara (UFC); DOS S. TEIXEIRA, ADUNIAS - Universidade Federal Do Ceara (UFC); DE OLIVEIRA, MARCIO - Universidade Federal Do Ceara (UFC); Ferreira, Jorge; DA S. SALES, JONNATHAN - Universidade Federal Do Ceara (UFC); CANJA, JUVENALDO - Universidade Federal Do Ceara (UFC); DA C. BEZERRA, BRUNO - Universidade Federal Do Ceara (UFC)

Submitted to: Revista Brasileira de Engenharia Agricola e Ambiental
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2024
Publication Date: 2/8/2024
Citation: de Oliveira, A.C., de Lacerda, C.F., Cavalcante, S., dos S. Teixeira, A., de Oliveira, M.R., Ferreira, J.F., da S. Sales, J.R., Canja, J.F., da C. Bezerra, B.M. 2024. Salt tolerance and foliar spectral responses in seedlings of four ornamental herbaceous species. Revista Brasileira de Engenharia Agricola e Ambiental. 28(5). Article e278645. https://doi.org/10.1590/1807-1929/agriambi.v28n5e276677.
DOI: https://doi.org/10.1590/1807-1929/agriambi.v28n5e276677

Interpretive Summary: Salinity is one of the main abiotic stresses that hinders plant yield and survival in arid and semiarid regions worldwide. The use of biostimulants based on seaweed extract may mitigate the deleterious effects of salinity stress on plant growth and development. Thus, our objective was to evaluate the growth, physiological parameters, and the visual characteristics of two tropical ornamental species cultivated with saline water and treated with Ascophyllum nodosum extract. The tropical ornamental species Silver Cock’s Comb (moderately salt tolerant) and Madagascar periwinkle (moderately salt sensitive) were irrigated with three levels of saline irrigation water and treated with four concentrations of seaweed extract. Salinity negatively affected all morphophysiological characteristics and the visual quality of both species, especially Madagascar periwinkle. Irrigation-water salinities up to 2.5 dS/m favored the visual quality and increased the purchase preference for the Madagascar periwinkle. The use of intermediate concentrations of the algae extracts partially mitigated the effects of salt stress on biomass production and leaf gas exchange. However, these positive responses decreased with the highest salinity of the irrigation water and depended on the salt tolerance of the species. These results may be useful for nursery businesses and growers of ornamental plants in semiarid areas where fresh water is scarce, or its quality has deteriorated due to salinization of groundwater caused by seawater intrusion.

Technical Abstract: The use of biostimulants based on seaweed extract may mitigate the deleterious effects of salt stress on plant growth and physiology. Thus, our objective was to evaluate the growth, physiological indices, and visual characteristics of two tropical ornamental species cultivated with saline waters and treated with Ascophyllum nodosum extract. The experiment was carried out in a tropical semiarid climate, from June to August 2021, under greenhouse conditions. The experimental design was a complete randomized block, arranged in split plots, with the main plots constituted of three levels of electrical conductivity of the irrigation water - ECw (0.5; 2.5 and 4.5 dS/m), the subplots of four concentrations of seaweed extract (0, 400, 800 and 1200 mg/L), and the sub-subplots corresponded to two tropical ornamental herbaceous species: Celosia argentea (moderately salt tolerant) and Catharanthus roseus (moderately salt sensitive). Salinity negatively affected the morphophysiological characteristics and visual quality of both species, especially C. roseus. The ECw of 0.5 and 2.5 dS/m favored the visual quality and greater purchase preference in the C. argentea species. The use of intermediate concentrations of the algae extracts partially mitigated the effects of salt stress on biomass production and leaf gas exchange. However, these positive responses decreased with the intensification of salt stress and depended on the salt tolerance of the species.